Ensure that drivers set max_num_buffers to a value >= 32.
For now there is no reason for drivers to request a lower
limit and doing so might potentially cause userspace issues.
Note that the old check of > MAX_BUFFER_INDEX was pointless
since q->max_num_buffers was already limited to MAX_BUFFER_INDEX
or less.
Also add a sanity check in __vb2_init_fileio(), returning
-ENOSPC if a driver returns more than 32 buffers from
VIDIOC_REQBUFS with count = q->min_reqbufs_allocation.
The vb2_fileio_data struct only support up to 32 buffers,
so we need a check there.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
---
As per an earlier discussion about whether max_num_buffers can be less
than 32.
---
drivers/media/common/videobuf2/videobuf2-core.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index b6bf8f232f48..282ef42f8f8e 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -2503,7 +2503,7 @@ int vb2_core_queue_init(struct vb2_queue *q)
WARN_ON(!q->ops->buf_queue))
return -EINVAL;
- if (WARN_ON(q->max_num_buffers > MAX_BUFFER_INDEX) ||
+ if (WARN_ON(q->max_num_buffers < VB2_MAX_FRAME) ||
WARN_ON(q->min_queued_buffers > q->max_num_buffers))
return -EINVAL;
@@ -2766,6 +2766,12 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
ret = vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
if (ret)
goto err_kfree;
+ /* vb2_fileio_data supports max VB2_MAX_FRAME buffers */
+ if (fileio->count > VB2_MAX_FRAME) {
+ dprintk(q, 1, "fileio: more than VB2_MAX_FRAME buffers requested\n");
+ ret = -ENOSPC;
+ goto err_reqbufs;
+ }
/*
* Userspace can never add or delete buffers later, so there
--
2.43.0
